1. Field of the invention
This invention relates generally to electrothermal utensils, more particularly, it relates to an electrothermal cooker having a plurality of improved thermal insulator located between a casing and an inner pot, and a plurality of improved supporting means arranged between the inner pot and a pot base with better heat insulation and support effect.
2. Description of the prior art
A conventional electrothermal cooker, as disclosed in U.S. Pat. No. 4,995,312, mainly comprises a metallic pot and a heat-generating resistor, wherein the resistor is used to heat the pot up to 150.degree. C. or more; as the pot is enclosed by a generic plastic casing that cannot stand temperature higher than 150.degree. C., hence, an air layer is formed in the circular wall and the pot base of the pot for segregation of the plastic casing; the metallic pot is isolated by the air layer except that it is connected with a thermo-insulating ring, which also contacts the upper rim of the casing.
However, as the thermo-insulating ring is made of high-priced polyurethane or polyester, the competitive capability of the foregoing electrothermal cooker is inevitably weakened. In view of the defect, this invention is to provide an improved low-cost thermo-insulating structure with excellent efficacy for the electrothermal cooker.